I've been working a lot with the adwords system the past week, when I first started my campaigns I had my adsense ads up on my site, I was still getting a lot of impressions on adwords and clicks and my adsense was pretty much covering my adwords expense. The last couple of days my adwords impressions slowed to a crawl, I had been talking with the support team and they couldn't offer me much advice, even saying the problem was strange and that they were forwarding it to a specialist. Today I got the idea to take off all of my adsense ads and then the impressions started right back up again. My website is by no means a "link farm", its a social / employment network and could do find (hopefully better) without adsense. I had been using it while I got the site going until I can either sell my own ads or use a more exclusive ad network. Anyways I'm wondering if anyone else has noticed this. Also, do you think that if I have ads from another ad network on my site that Google will penalize me for this as well or is this just some thing they do to prevent adsense / adwords arbitrage?